Support dragging texts into Android WebView.

content/browser/android/content_view_core_impl.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/content_view_core_impl.h"
 
 #include <stddef.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/output/begin_frame_args.h"
 #include "content/browser/accessibility/browser_accessibility_manager_android.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
 #include "content/browser/android/gesture_event_type.h"
 #include "content/browser/android/interstitial_page_delegate_android.h"
 #include "content/browser/android/java/gin_java_bridge_dispatcher_host.h"
@@ skipping 21 matching lines @@
 #include "content/public/browser/ssl_host_state_delegate.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/menu_item.h"
 #include "content/public/common/user_agent.h"
 #include "jni/ContentViewCore_jni.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/android/view_android.h"
 #include "ui/android/window_android.h"
+#include "ui/base/clipboard/clipboard.h"
 #include "ui/events/android/motion_event_android.h"
 #include "ui/events/blink/blink_event_util.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/geometry/point_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/geometry/size_f.h"
 
 using base::android::AttachCurrentThread;
 using base::android::ConvertJavaStringToUTF16;
@@ skipping 16 matching lines @@
   // Popup item is of type group
   POPUP_ITEM_TYPE_GROUP,
 
   // Popup item is disabled
   POPUP_ITEM_TYPE_DISABLED,
 
   // Popup item is enabled
   POPUP_ITEM_TYPE_ENABLED,
 };
 
+// A copy of possible DragEvent.getActions().
+// https://developer.android.com/reference/android/view/DragEvent.html
+enum DragEventActions {
+  ACTION_DRAG_STARTED = 1,

[Ted C, 2016/06/30 00:15:42]

any reason we don't generate these the same way we do MotionEvent jni bindings?

from content/public/android/BUILD.gn

generate_jar_jni("jar_jni") {
  jni_package = "content"
  classes = [
    "java/util/HashSet.class",
    "android/view/MotionEvent.class",
  ]
}

Seems like we could add DragEvent here as well.

[hush (inactive), 2016/06/30 18:19:06]

Didn't know we could do that.
Done

+  ACTION_DRAG_LOCATION,
+  ACTION_DROP,
+  ACTION_DRAG_ENDED,
+  ACTION_DRAG_ENTERED,
+  ACTION_DRAG_EXITED,
+};
+
 const void* const kContentViewUserDataKey = &kContentViewUserDataKey;
 
 int GetRenderProcessIdFromRenderViewHost(RenderViewHost* host) {
   DCHECK(host);
   RenderProcessHost* render_process = host->GetProcess();
   DCHECK(render_process);
   if (render_process->HasConnection())
     return render_process->GetHandle();
   return 0;
 }
@@ skipping 1362 matching lines @@
                                               const JavaParamRef<jobject>& jobj,
                                               jboolean opaque) {
   if (GetRenderWidgetHostViewAndroid()) {
     if (opaque)
       GetRenderWidgetHostViewAndroid()->SetBackgroundColorToDefault();
     else
       GetRenderWidgetHostViewAndroid()->SetBackgroundColor(SK_ColorTRANSPARENT);
   }
 }
 
+void ContentViewCoreImpl::OnDragEvent(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& jobj,
+    jint action,
+    jint x,
+    jint y,
+    jint screen_x,
+    jint screen_y,
+    const base::android::JavaParamRef<jobjectArray>& j_mimeTypes,
+    const base::android::JavaParamRef<jstring>& j_content) {
+  WebContentsViewAndroid* wcva = static_cast<WebContentsViewAndroid*>(
+      static_cast<WebContentsImpl*>(web_contents())->GetView());
+
+  const gfx::Point location(x, y);
+  const gfx::Point screen_location(screen_x, screen_y);
+
+  std::vector<base::string16> mime_types;
+  base::android::AppendJavaStringArrayToStringVector(env, j_mimeTypes,
+                                                     &mime_types);
+  switch (action) {
+    case ACTION_DRAG_ENTERED: {
+      std::vector<DropData::Metadata> metadata;
+      for (const base::string16& mime_type : mime_types) {
+        metadata.push_back(DropData::Metadata::CreateForMimeType(
+            DropData::Kind::STRING, mime_type));
+      }
+      wcva->OnDragEntered(metadata, location, screen_location);
+      break;
+    }
+    case ACTION_DRAG_LOCATION: {
+      wcva->OnDragUpdated(location, screen_location);
+      break;
+    }
+    case ACTION_DROP: {
+      base::string16 text_to_drop = ConvertJavaStringToUTF16(env, j_content);
+      DropData drop_data;
+      drop_data.did_originate_from_renderer = false;
+      for (const base::string16& mime_type : mime_types) {
+        if (base::EqualsASCII(mime_type, ui::Clipboard::kMimeTypeURIList)) {
+          drop_data.url = GURL(text_to_drop);
+        } else if (base::EqualsASCII(mime_type, ui::Clipboard::kMimeTypeText)) {
+          drop_data.text = base::NullableString16(text_to_drop, false);
+        } else {
+          drop_data.html = base::NullableString16(text_to_drop, false);
+        }
+      }
+
+      wcva->OnPerformDrop(&drop_data, location, screen_location);
+      break;
+    }
+    case ACTION_DRAG_EXITED:
+      wcva->OnDragExited();
+      break;
+    default:  // STARTED and ENDED. Nothing meaningful to do.
+      break;
+  }
+}
+
 void ContentViewCoreImpl::RequestTextSurroundingSelection(
     int max_length,
     const base::Callback<
         void(const base::string16& content, int start_offset, int end_offset)>&
         callback) {
   DCHECK(!callback.is_null());
   RenderFrameHost* focused_frame = web_contents_->GetFocusedFrame();
   if (!focused_frame)
     return;
   if (GetRenderWidgetHostViewAndroid()) {
@@ skipping 95 matching lines @@
     return ScopedJavaLocalRef<jobject>();
 
   return view->GetJavaObject();
 }
 
 bool RegisterContentViewCore(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content